(a) Field of the Invention
The present invention relates to a high strength composite material using nanocarbons and metal nanoparticles coated with graphenes. More particularly, the present invention relates to a high strength polymer filament for a 3D printer for an FDM-type realizing a function of the metal nanoparticles coated with the graphenes and the carbon nanotubes, and improving the strength and durability of the polymer, and a manufacturing method thereof, by dispersing the nanocarbons and the metal nanoparticles coated with the graphenes in a biocompatibility polymer resin.
(b) Description of the Related Art
Recently, due to technology development including 3D printing material development and economic availability, a 3D printer capable of molding a three-dimensional object is being used in a variety of industry fields, and receptivity of the technology thereof is increasing. The 3D printing is a method of molding a product by transmitting a 3D design drawing of a computer to the 3D printer, and in the product molding method of the 3D printer, there are a method (fused deposition modeling; FDM) in which a raw material such as a resin is melted and then compressed through a nozzle to stack a thin hardened layer, a method (selective laser sintering; SLS) in which the raw material is heated by a laser to be sintered, and a method (stereo lithography apparatus; SLA) in which a laser is projected in a tank containing a photo-curable resin to be cured.
Among these methods, the 3D printer of the method (FDM type) of melting and stacking the filament has a simple structure of the apparatus and a simple program, and a low manufacturing cost compared with the other 3D printers, and for this reason, the 3D printer of the FDM type using the filament is advantageous for a large size and can be applied to various industrial fields, thereby trending to be popular in the home and industry.
Currently, plastic materials most widely used as the filament material that is the material of the FDM-type printer are acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA), and among them, the ABS is inexpensive and has a good durability, however there is a drawback that it requires a high temperature of about 220° C. during processing and a heating bed to prevent shrinkage when outputting. On the other hand, the PLA is biodegradable and environmentally-friendly, and has easier output than the ABS, thereby getting a lot of the limelight, however the strength and the durability are poor and the conductivity is low such that use thereof in various fields such as for electrical and electronic components and for biotechnology is limited.
As a method to improve the strength of the polymer resin such as the PLA, a ceramic, a graphene, a carbon nanotube, or the like is added to form the filament, however dispersion thereof is not easy in the polymer such that there are drawbacks that the strength is rather weak or the strength does not increase beyond a certain level. Particularly, due to metal particles having different physical and chemical characteristics from the polymer base, aggregation is easily generated in the polymer base such that a function as the filler is limited.
On the other hand, studies on nanocarbon filaments have been performed as follows. [M. G. Lee, et al., Journal of the Korean Society of Manufacturing Technology Engineers Conference, September 2014, 31-31] is 3D printer PLA filament research only using the carbon nanotubes as a reinforcing agent. Also, [Wendelin J Stark et al., 2008 Nanotechnology 19 445201] is research related to inkjet printing using Cu nanoparticles with a graphene coating, and [Z. Antar et al., Materials Letters 67, 2012, 210-214] as research related to a composite using carbon nanotubes does not disclose the 3D printer filament.
Accordingly, the 3D printer filament technique including the nanoparticles with the graphene coating and with remarkably improved strength has not been known up to now, and the development thereof is urgent.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.